<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .div1{
            width: 100px;
            height: 100px;
            background: red;
        }
        .div2{
            width: 100px;
            height: 100px;
            background: #6cff87;
        }
        .div3{
            width: 100px;
            height: 100px;
            background: #7872ff;
        }
        .div4{
            width: 100px;
            height: 100px;
            background: #ee60ff;
        }

        .div1:hover{
            height: 50px;
        }
    </style>
</head>
<body>

    <div class="div1">
        div1
    </div>
    <div class="div2">
        div1
    </div>
    <div class="div3">
        div1
    </div>
    <div class="div4">
        div1
    </div>


</body>
</html>
